Is the opening of Metro Bank this morning the start of a revolution in British banking, as claimed by its intriguing founder, Vernon Hill? Metro is making some bold claims, but the high street citadels of finance will not be toppled overnight.

True, Metro is the first new high street bank in this country for more than a century, and a challenge to the tarnished incumbents is long overdue. But its American-style "fun" marketing, based on Hill's experience in the fast food industry, may not be enough to win over jaded British account holders.

Metro is the brainchild of Hill, a US entrepreneur who was ejected by regulators in the US from Commerce Bancorp over that bank's business dealings with various members of his family. The Financial Services Authority, however, has cleared him to serve as a non-executive director.

The bank's big selling point, apart from jollity, is convenience: longer opening hours and seven days a week banking, plus 15-minute account opening with a debit and credit card – though whether credit-crunched Britain needs more easy plastic is a moot point.

It is not alone in thinking there is a gap in the market: Virgin plans to open a high street banking operation next year; Tesco is planning a bank for its customers; M&S Money, with the backing of HSBC, is considering expansion into current accounts, and City grandees Lord Levene and Sir David Walker are throwing their hats into the ring with Project New Bank.

The newbies are on to something. UK banking needs a breath of fresh air, and if the government concludes it wants to see more narrow utility banks that concentrate on simple savings and loans business as distinct from casino activities, it may work in its favour.

But the established players, despite blotted copybooks, are deeply entrenched. There is a reason there have been no new banks on the high street in this country for more than 100 years: the barriers to entry are formidable.

New banks have to win the trust of customers as well as satisfying regulators, and for the likes of Tesco and Virgin, banking brings significant risk to their mainstream brand – as they may alienate customers if they have to turn them down for loans or mortgages. Retail culture and banking prudence don't necessarily mix.

Even the pragmatic business of setting up shop on the high street is not easy, as new entrants will be competing for the branches discarded by Northern Rock and Lloyds. But the biggest barrier is sheer inertia. Recent research by uSwitch.com found that while 57% welcomed a fresh alternative to "the big four", only 38% would consider moving their current account to a new bank.

Spanish bank Santander, which took over Abbey, Bradford & Bingley and Alliance & Leicester, is having some success with its campaign offering £100 to customers who move their primary current account. It is likely to reveal today that it is on target to open more than a million new current accounts this year, helping it to half-year profits in the UK of almost £900m.

Santander is ruthless in its approach to integrations, exerting an iron grip on costs, but its customer service still leaves a lot to be desired. The company came bottom of a Which? magazine survey of savings account holders this week.

Previous attempts to revolutionise banking have all fizzled out. First Direct in its heyday was expected to shake the entire market, but the behemoths trundled on regardless. Sir James Crosby, the former chief executive of HBOS, used to bang on endlessly about how he would "eat the big four's lunch": we all know how that turned out.

So back to the question of whether there will be a successful revolution in banking: like Zhou Enlai, when asked for his assessment of events in France in 1789, my view is it's far too early to say.